Rule #1: When making a casserole or layered dish, always place the biggest pieces on the bottom. This will give you a solid, sturdy foundation. If you place the biggest pieces in the middle, that which is underneath with crumble.
Life is a layered dish. Relationships have a little of this, a little of that, and it's easy to package them nicely, garnish creatively, and hope no one notices. But you will. You will notice, and you will taste it, feel it, and at some point, it will crumble.
The most important thing, person, or belief in your life is already your foundation. Is it big enough to sustain, holding together the rest of this dish we call life? If not, it will crumble, and that's ok, it's a sure sign it's not the right foundation.